Many industrial and retail buildings will typically have doorways or large rooms that must be open for extended periods of time for ingress and egress of personnel and material. Since the open doorway and the rooms may be quite large, making it extremely difficult to control the interior temperature within the room or building, it is desirable to create an air-blocking barrier. In other applications, it may be desirable to partition the large rooms or spaces into smaller sections, for example, in order to separate work cells or assembly lines or prevent debris and the like from leaving the space. Attempts to control the passage of conditioned air through door openings and within the large spaces or to partition large rooms have included power roll-up doors and strip curtain doors.
Conventional strip curtains consist of a plurality of strips of overlapping and abutting curtain-like material, typically made of plastic, vinyl, fabric or the like, which create a flexible barrier across the doorway and/or space. To create an air-blocking seal, the strips may be hung so as to span substantially the entire doorway or space, typically from the floor to the top of the doorway or ceiling. The strips may also be disposed in the space so as to partition the space without creating an air blocking seal. The individual strips deflect to allow passage of personnel and material through the barrier. A perceived disadvantage of such strip curtains is that the strips brush against the personnel, product or material as they pass through the barrier. This contact may be irritating to personnel and, in the case of certain products, such as food or delicate products, such contact may cause damage, infection or other harm as the material passes through the barrier.
Conventional roll-up doors typically consist of a solid flexible curtain or barrier, typically made of plastic, vinyl, fabric or the like, which fully covers the door opening. The curtain is attached to a power roller or drum at the top of the opening which rotates so as to raise and lower the curtain. Unfortunately, the power roll-up doors are expensive and require complicated actuation and other assemblies such as high speed motors, break-away bars, belting mechanisms and the like to operate efficiently. The power roll-up doors also require complicated safety devices in the event that the door does not properly or completely open when personnel and material pass through it.